bus: sunxi-rsb: make sunxi_rsb_bus const

Now that the driver core can properly handle constant struct bus_type,
move the sunxi_rsb_bus variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20240204-bus_cleanup-bus-v1-1-bda309c4b829@marliere.net
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>

bus: sunxi-rsb: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Link: https://lore.kernel.org/r/20231109202830.4124591-8-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

bus: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20230803-dt-header-cleanups-for-soc-v2-16-d8de2cc88bff@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

bus: sunxi-rsb: Convert to devm_platform_ioremap_resource()

Use devm_platform_ioremap_resource() to simplify code.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20230706072042.31296-1-frank.li@vivo.com
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>

driver core: make struct bus_type.uevent() take a const *

The uevent() callback in struct bus_type should not be modifying the
device that is passed into it, so mark it as a const * and propagate the
function signature changes out into all relevant subsystems that use
this callback.

Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230111113018.459199-16-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

of: device: make of_device_uevent_modalias() take a const device *

of_device_uevent_modalias() does not modify the device pointer passed to
it, so mark it constant. In order to properly do this, a number of
busses need to have a modalias function added as they were attempting to
just point to of_device_uevent_modalias instead of their bus-specific
modalias function. This is fine except if the prototype for a bus and
device type modalias function diverges and then problems could happen. To
prevent all of that, just wrap the call to of_device_uevent_modalias()
directly for each bus and device type individually.

Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Jernej Skrabec <jernej.skrabec@gmail.com>
Cc: Samuel Holland <samuel@sholland.org>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Liang He <windhl@126.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Corentin Labbe <clabbe@baylibre.com>
Cc: Zou Wei <zou_wei@huawei.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-sunxi@lists.linux.dev
Cc: dri-devel@lists.freedesktop.org
Cc: devicetree@vger.kernel.org
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230111113018.459199-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

bus: sunxi-rsb: Fix error handling in sunxi_rsb_init()

The sunxi_rsb_init() returns the platform_driver_register() directly
without checking its return value, if platform_driver_register() failed,
the sunxi_rsb_bus is not unregistered.
Fix by unregister sunxi_rsb_bus when platform_driver_register() failed.

Fixes: d787dcdb9c8f ("bus: sunxi-rsb: Add driver for Allwinner Reduced Serial Bus")
Signed-off-by: Yuan Can <yuancan@huawei.com>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20221123094200.12036-1-yuancan@huawei.com
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>

bus: sunxi-rsb: Support atomic transfers

When communicating with a PMIC during system poweroff (pm_power_off()),
IRQs are disabled and we are in a RCU read-side critical section, so we
cannot use wait_for_completion_io_timeout(). Instead, poll the status
register for transfer completion.

Fixes: d787dcdb9c8f ("bus: sunxi-rsb: Add driver for Allwinner Reduced Serial Bus")
Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20221114015749.28490-3-samuel@sholland.org
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>

bus: sunxi-rsb: Remove the shutdown callback

Shutting down the RSB controller prevents communicating with a PMIC
inside pm_power_off(), since that gets called after device_shutdown(),
so it breaks system poweroff on some boards.

Reported-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Tested-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Fixes: 843107498f91 ("bus: sunxi-rsb: Implement suspend/resume/shutdown callbacks")
Signed-off-by: Samuel Holland <samuel@sholland.org>
Link: https://lore.kernel.org/r/20221114015749.28490-2-samuel@sholland.org
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_56.RULE (part 2)

Based on the normalized pattern:

this file is licensed under the terms of the gnu general public
license version 2 this program is licensed as is without any warranty
of any kind whether express or implied

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

bus: sunxi-rsb: Fix the return value of sunxi_rsb_device_create()

This code is really spurious.
It always returns an ERR_PTR, even when err is known to be 0 and calls
put_device() after a successful device_register() call.

It is likely that the return statement in the normal path is missing.
Add 'return rdev;' to fix it.

Fixes: d787dcdb9c8f ("bus: sunxi-rsb: Add driver for Allwinner Reduced Serial Bus")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Samuel Holland <samuel@sholland.org>
Tested-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/ef2b9576350bba4c8e05e669e9535e9e2a415763.1650551719.git.christophe.jaillet@wanadoo.fr

bus: sunxi-rsb: Fix shutdown

Function sunxi_rsb_hw_exit() is sometimes called with pm runtime
disabled, so in such cases pm_runtime_resume() will fail with -EACCES.

Instead of doing whole dance of enabling pm runtime and thus clock just
to disable it again immediately, just check if disabling clock is
needed. That way calling pm_runtime_resume() is not needed at all.

Fixes: 4a0dbc12e618 ("bus: sunxi-rsb: Implement runtime power management")
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20211121083537.612473-1-jernej.skrabec@gmail.com

bus: Make remove callback return void

The driver core ignores the return value of this callback because there
is only little it can do when a device disappears.

This is the final bit of a long lasting cleanup quest where several
buses were converted to also return void from their remove callback.
Additionally some resource leaks were fixed that were caused by drivers
returning an error code in the expectation that the driver won't go
away.

With struct bus_type::remove returning void it's prevented that newly
implemented buses return an ignored error code and so don't anticipate
wrong expectations for driver authors.

Reviewed-by: Tom Rix <trix@redhat.com> (For fpga)
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com> (For drivers/s390 and drivers/vfio)
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> (For ARM, Amba and related parts)
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Chen-Yu Tsai <wens@csie.org> (for sunxi-rsb)
Acked-by: Pali Rohár <pali@kernel.org>
Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org> (for media)
Acked-by: Hans de Goede <hdegoede@redhat.com> (For drivers/platform)
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-By: Vinod Koul <vkoul@kernel.org>
Acked-by: Juergen Gross <jgross@suse.com> (For xen)
Acked-by: Lee Jones <lee.jones@linaro.org> (For mfd)
Acked-by: Johannes Thumshirn <jth@kernel.org> (For mcb)
Acked-by: Johan Hovold <johan@kernel.org>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> (For slimbus)
Acked-by: Kirti Wankhede <kwankhede@nvidia.com> (For vfio)
Acked-by: Maximilian Luz <luzmaximilian@gmail.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> (For ulpi and typec)
Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com> (For ipack)
Acked-by: Geoff Levand <geoff@infradead.org> (For ps3)
Acked-by: Yehezkel Bernat <YehezkelShB@gmail.com> (For thunderbolt)
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> (For intel_th)
Acked-by: Dominik Brodowski <linux@dominikbrodowski.net> (For pcmcia)
Acked-by: Rafael J. Wysocki <rafael@kernel.org> (For ACPI)
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org> (rpmsg and apr)
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> (For intel-ish-hid)
Acked-by: Dan Williams <dan.j.williams@intel.com> (For CXL, DAX, and NVDIMM)
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com> (For isa)
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (For firewire)
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> (For hid)
Acked-by: Thorsten Scherer <t.scherer@eckelmann.de> (For siox)
Acked-by: Sven Van Asbroeck <TheSven73@gmail.com> (For anybuss)
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> (For MMC)
Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Finn Thain <fthain@linux-m68k.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20210713193522.1770306-6-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mfd/bus: sunxi-rsb: Make .remove() callback return void

The driver core ignores the return value of struct device_driver::remove
because there is only little that can be done. To simplify the quest to
make this function return void, let struct sunxi_rsb_driver::remove
return void, too. All users already unconditionally return 0, this
commit makes this obvious and ensures future users don't behave
differently. To simplify even further, make axp20x_device_remove()
return void instead of returning 0 unconditionally, too.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

bus: sunxi-rsb: Implement runtime power management

Gate the clock to save power while the controller is idle.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>

bus: sunxi-rsb: Implement suspend/resume/shutdown callbacks

Since system firmware is likely to use the RSB bus to communicate with a
PMIC while the system is suspended, we cannot make any assumptions about
the controller state after resuming. Thus it is important to completely
reinitialize the controller.

The RSB bus needs to be ready as soon as IRQs are enabled, to handle
wakeup event IRQs coming from the PMIC. Thus it uses NOIRQ callbacks.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>

bus: sunxi-rsb: Split out controller init/exit functions

This separates the resource acquisition from the hardware initialization
phase, so the hardware initialization can be repeated after system
suspend/resume. The same is done for the exit/remove function, except
that there is no resource deallocation phase due to the use of devres.

The requested RSB clock frequency is stored in `struct sunxi_rsb` so it
will be available when reinitializing the hardware.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>

bus: sunxi-rsb: Move OF match table

For some reason, this driver's OF match table was placed above the
probe/remove functions, far away from the platform_driver definition.
Adding device PM ops would move the table even farther away. Let's move
it to the usual place, right before the platform_driver.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>

bus: sunxi-rsb: Return correct data when mixing 16-bit and 8-bit reads

When doing a 16-bit read that returns data in the MSB byte, the
RSB_DATA register will keep the MSB byte unchanged when doing
the following 8-bit read. sunxi_rsb_read() will then return
a result that contains high byte from 16-bit read mixed with
the 8-bit result.

The consequence is that after this happens the PMIC's regmap will
look like this: (0x33 is the high byte from the 16-bit read)

% cat /sys/kernel/debug/regmap/sunxi-rsb-3a3/registers
00: 33
01: 33
02: 33
03: 33
04: 33
05: 33
06: 33
07: 33
08: 33
09: 33
0a: 33
0b: 33
0c: 33
0d: 33
0e: 33
[snip]

Fix this by masking the result of the read with the correct mask
based on the size of the read. There are no 16-bit users in the
mainline kernel, so this doesn't need to get into the stable tree.

Signed-off-by: Ondrej Jirman <megous@megous.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

bus: sunxi-rsb: Remove dev_err() usage after platform_get_irq()

We don't need dev_err() messages when platform_get_irq() fails now that
platform_get_irq() prints an error message itself when something goes
wrong. Let's remove these prints with a simple semantic patch.

// <smpl>
@@
expression ret;
struct platform_device *E;
@@

ret =
(
platform_get_irq(E, ...)
|
platform_get_irq_byname(E, ...)
);

if ( \( ret < 0 \| ret <= 0 \) )
{
(
-if (ret != -EPROBE_DEFER)
-{ ...
-dev_err(...);
-... }
|
...
-dev_err(...);
)
...
}
// </smpl>

While we're here, remove braces on if statements that only have one
statement (manually).

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>

sunxi-rsb: Include OF based modalias in device uevent

Include the OF-based modalias in the uevent sent when registering devices
on the sunxi RSB bus, so that user space has a chance to autoload the
kernel module for the device.

Fixes a regression caused by commit 3f241bfa60bd ("arm64: allwinner: a64:
pine64: Use dcdc1 regulator for mmc0"). When the axp20x-rsb module for
the AXP803 PMIC is built as a module, it is not loaded and the system
ends up with an disfunctional MMC controller.

Fixes: d787dcdb9c8f ("bus: sunxi-rsb: Add driver for Allwinner Reduced Serial Bus")
Cc: stable <stable@vger.kernel.org> # 4.4.x 7a3b7cd332db of: device: Export of_device_{get_modalias, uvent_modalias} to modules
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

bus: Convert to using %pOF instead of full_name

Now that we have a custom printf format specifier, convert users of
full_name to use %pOF instead. This is preparation to remove storing
of the full path string for each node.

Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

drivers: sunxi-rsb: fix error output type

"len" is actually a size_t in this function here, so properly annotate
the dev_err printf type to allow compilation for 64-bit architectures.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

bus: sunxi-rsb: Fix peripheral IC mapping runtime address

0x4e is the runtime address normally associated with perihperal ICs.
0x45 is not a valid runtime address.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Olof Johansson <olof@lixom.net>

bus: sunxi-rsb: Fix primary PMIC mapping hardware address

The primary PMICs use 0x3a3 as their hardware address, not 0x3e3.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Olof Johansson <olof@lixom.net>

bus: sunxi-rsb: unlock on error in sunxi_rsb_read()

Don't forget to unlock before returning an error code.

Fixes: d787dcdb9c8f ('bus: sunxi-rsb: Add driver for Allwinner Reduced Serial Bus')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

bus: sunxi-rsb: Add driver for Allwinner Reduced Serial Bus

Reduced Serial Bus (RSB) is an Allwinner proprietery interface
used to communicate with PMICs and other peripheral ICs.

RSB is a two-wire push-pull serial bus that supports 1 master
device and up to 15 active slave devices.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Olof Johansson <olof@lixom.net>